(a) Field of the Invention
The present invention relates to an intake and exhaust device of a cylinder. More particularly, the present invention relates to an intake and exhaust device of a cylinder for opening and closing an intake port and an exhaust port.
(b) Description of the Related Art
Generally, an intake port and an exhaust port are formed in an upper portion of a cylinder. Valves are provided in a cylinder head to open and close the ports. Crankshaft energy causes the valves to open and close the ports.
Particularly, a valve can impact with a piston when the valve does not move with appropriate timing. Further, a sealing seat that comes into contact with a combustion gas provided at a head side of the valve can be worn away. When the wearing amount becomes increased, engine performance is deteriorated and a vehicle cannot be started.
A mechanism for transmitting a driving torque from the crankshaft to the valve of the cylinder head is needed to drive the valve, but the mechanism is complicated and causes a power loss. Recently, a chain has been used as a torque transmitting device, but the cost for providing a mechanism to drive the valve has increased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.